Method and system for guiding user positioning of a robot

ABSTRACT

A system and process is provided for dynamically positioning or repositioning a robot in a surgical context based on workspace and task requirements, manipulator requirements, or user preferences to execute a surgical plan. The system and method accurately determines and indicates an optimal position for a robot with respect to a patient&#39;s anatomy before or during a surgical procedure. Optimal positions for a robot are intuitively indicated to a user, surgical procedures can illustratively include surgery to the knee joint, hip joint, spine, shoulder joint, elbow joint, ankle joint, jaw, a tumor site, joints of the hand or foot, and other appropriate surgical sites.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of U.S. Provisional Patent ApplicationSer. No. 62/300,234 filed Feb. 26, 2016, which is incorporated herein byreference.

FIELD OF THE INVENTION

The present invention in general relates to the field of robotic andcomputer assisted surgery; and in particular, to a new and usefulprocess and system for dynamically positioning a surgical robot based onworkspace and task requirements.

BACKGROUND OF THE INVENTION

Robotic surgical procedures have become a preferred medical techniquefor many complex surgeries that require a high level of precision.Computer assisted surgical devices such as robots are gaining popularityas a tool to pre-operatively plan and precisely execute the plan toensure an accurate final position and orientation of a prosthetic withina patient's bone that can improve long term clinical outcomes andincrease the survival rate of a prosthesis compared to a manuallyperformed surgery. In general, the computer assisted surgical systemsinclude two components, an interactive pre-operative planning softwareprogram and a computer assisted surgical device that utilizes thepre-operative data from the software to assist the surgeon in preciselyexecuting the procedure.

Conventional interactive pre-operative planning software generates athree dimensional (3-D) model of the patient's bony anatomy from acomputed tomography (CT) or magnetic resonance imaging (MRI) imagedataset of the patient. A set of 3-D computer aided design (CAD) modelsof the manufacturer's prosthesis are pre-loaded in the software thatallows the user to place the components of a desired prosthesis to the3-D model of the bony anatomy to designate the best fit, position, andorientation of the prosthesis to the bone. The final surgical plan datamay include instructions for a surgical device, such as a set of pointsin a cut-file or a set of haptic virtual boundaries, to precisely modifya volume of tissue or assist a surgeon in modifying the tissue toachieve the goals of the plan.

Common surgical procedures performed with robotic assistance are totaland partial joint replacements. Joint replacement (also called primaryjoint arthroplasty) is a surgical procedure in which the articulatingsurfaces of a joint are replaced with prosthetic components. Jointreplacement has become a successful procedure, especially for hips,knees, shoulders, and ankles, and allows people to restore functionalitywhile greatly reducing pain associated with osteoarthritis. Commercialrobotic systems for executing total and partial joint replacementsinclude the TSolution One™ Surgical System (THINK Surgical Inc.,Fremont, Calif.) and the RIO® Interactive Orthopedic System(Stryker-Mako, Ft. Lauderdale, Fla.). Examples of these robotic systemsare described in greater detail in U.S. Pat. Nos. 5,086,401 and7,206,626.

To perform a joint replacement procedure with a robotic system, thecorrect positioning of the robot with respect to the patient iscritical. For example, with the TSolution One™ Surgical System, amoveable base is currently manually maneuvered next to the targetanatomy and fixed into a position using a braking mechanism on themoveable base. A fixator arm is then secured to the bone to fix the boneto the system. Subsequently, the position and orientation (POSE) of thebone are registered to the surgical plan and to the system using atracking mechanism (e.g., an optical tracking system, a mechanicaltracking system). After registration, the robotic system determines ifan end-effector tool of the robot can perform a surgical task (i.e.,execute the surgical plan) on the anatomy. All of the points orboundaries in the task should be within the workspace of the robot, andhence all the points or boundaries should be reachable by the robot. Inother words, the end-effector tool needs to reach all of the points orboundaries designated in the surgical plan with respect to the targetanatomy.

The primary problem with the current approach is limited a prioriinformation for the optimal position for the robot base prior toapproaching the patient with the robot. Therefore, if the robotic systemdetermines the end-effector tool is unable to perform the surgical taskwith the base already fixed relative to the patient, the base may needto be repositioned and the bone re-registered. In addition, there is noguarantee that the new position for the base is suitable to perform thesurgical task. There is also the possibility that when the position ofthe base with respect to the anatomy changes, this causes the designatedpoints or boundaries to also change within the workspace of the robot.Some of these points or boundaries may be pushed out of the workspaceand become unreachable. Sometimes a change in the height of the robot interms of the base height is sufficient (i.e., an upward or downwardtranslation of the manipulator arm), while in other cases the positionof the base needs to be completely re-positioned with respect to theanatomy. This becomes more important in cases of total knee arthroplasty(TKA) where the end-effector tool is often reoriented several times. Allof these problems can greatly increase the time needed to perform theoperation, especially if the target anatomy needs to be fixed to therobotic system (e.g., see robotic-bone fixation as described in U.S.Pat. No. 5,086,401).

Computer aid has also been limited in many instances to the execution ofa surgical plan with cut parameters that are based on limited input forinstance input that is limited to the dimensions of a cutting cavitycorrelating to a particular prosthesis, and the position of theprosthesis in a bone model. As a result, a surgeon must still manuallycontend with soft tissue issues. In addition, there are other parametersof the robotic system that should be addressed prior to positioning thebase. This may include how the manipulator arm articulates to performthe task and whether any of those articulations may cause a fault orerror such as a singularity fault. There may be preferences by a surgeonor surgical team to have particular access points or corridors to theoperating site with which the robotic system may otherwise interfere. Ifan optical tracking system is present, the base should be positioned tomaintain the line-of-sight between any tracking markers and the trackingsystem throughout the entire procedure. By simply guessing a positionfor the base next to the anatomy, these parameters will not be optimal.

Finally, once an optimal position for the base has been determined, thatposition needs to be conveyed to the surgical team in an intuitive andaccurate manner. A few millimeters in base position could have an effecton the surgical procedure workflow and the overall surgical time.

Thus, there exists a need for a system and method to optimally positionor reposition a robotic system with respect to a patient's anatomyaccording to task requirements, manipulator requirements, or userpreferences to execute a surgical plan. There is a further need tointuitively indicate the optimal position for the robotic system to auser.

SUMMARY OF THE INVENTION

A process is provided for positioning a robot in an operating roomcontaining a surgical table, the robot having a moveable base, amanipulator arm, and an end effector tool. The process includes:evaluating an initial position of the moveable base in the operatingroom, the robot having a programmed surgical plan; moving the moveablebase from the initial position towards the surgical table with collisionavoidance mobility software to a first determined position; stopping themoveable base; and engaging the manipulator arm and the end effectortool.

A process is provided for positioning a robot in an operating roomcontaining a surgical table with a bone thereon, the robot having amoveable base, a manipulator arm, an end effector tool attached to themanipulator arm, and a computer containing a surgical plan program andhardware to communicate the plan to the manipulator arm. The processincludes assuming a certain position and orientation (POSE) with themanipulator arm to form an axis of the end effector tool that representsa desired position of an axis of the bone, and moving the moveable baseor the registered bone to approximately align the axis of the registeredbone and the axis of the end effector tool.

A process is provided for positioning a robot in an operating roomcontaining a surgical table, the robot having a moveable base, amanipulator arm, and an end effector tool. The process includes:determining a first position of the moveable base in the operating room,the robot having a programmed surgical plan; moving the moveable basefrom an initial position towards the surgical table to the determinedfirst position; stopping the moveable base; and engaging the manipulatorarm and the end effector tool.

A robotic surgical system operating on a floor is provided. The roboticsurgical system includes a computer assisted surgical robot having abase, an end effector tool projecting from the robot, fiducial markerarrays and an optical tracking system for tracking or navigating the endeffector relative to a subject bone. The surgical system furtherincludes a surgical plan of operations to be performed on the subjectbone, and a laser, a 2-D image, or holographic image projector toproject an image of a desired position for the base of the robot on thefloor to comply with at least one operation of the surgical plan ofoperations.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further detailed with respect to the followingdrawings. These figures are not intended to limit the scope of thepresent invention but rather illustrate certain attributes thereof.

FIG. 1 depicts an inventive operating room with a surgical system havinga robotic computer-assisted device, a computing system, and a trackingsystem, where the robotic device has a positioning indicator to providea user with an indication of an optimal position for the robot withrespect to a patient's anatomy in accordance with embodiments of theinvention;

FIG. 2 illustratively depicts an inventive operating room with a roboticcomputer-assisted device having an indicator that is indicating anoptimal position for the base, and other sensors for guiding the base ofthe device to the optimal position in accordance with embodiments of theinvention;

FIG. 3 illustratively depicts the use of an augmented reality device fordisplaying the optimal position for a base of a robotic surgical devicein accordance with embodiments of the invention; and

FIG. 4 illustratively depicts an inventive operating room with a roboticcomputer-assisted device without any additional indicators or sensors,wherein the robotic base is guided to an optimal position according tothe orientation of the robot manipulator arm in accordance withembodiments of the invention.

DESCRIPTION OF THE INVENTION

The present invention has utility as a system and process fordynamically positioning or repositioning a robot in a surgical contextbased on workspace and task requirements, manipulator requirements, oruser preferences. Embodiments of the inventive system and methodaccurately determine and indicate an optimal position for a robot withrespect to a patient's anatomy before or during a surgical procedure.

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention. The invention described herein illustratively uses total kneearthroplasty (TKA) as an example. Although total knee arthroplasty isone procedure that can benefit from the disclosed embodiments othersurgical procedures can illustratively include surgery to the kneejoint, hip joint, spine, shoulder joint, elbow joint, ankle joint, jaw,a tumor site, joints of the hand or foot, and other appropriate surgicalsites.

With reference to the figures, FIG. 1 illustrates an embodiment of asurgical system and operating room (OR) for a robotic assisted surgicalprocedure. The surgical system 100 generally includes a surgical robot102, a computing system 104, and a tracking system 106.

The surgical robot 102 includes a moveable base 108, a manipulator arm110 connected to the movable base 108, an end-effector flange 112located at a distal end of the manipulator arm 110, and an end-effectortool 113 having a tool tip 115, where the tool 113 z is removablyattached to the end-effector flange 112. The moveable base 108 mayinclude a set of wheels 117 to maneuver the base 108, which may be fixedinto position using a braking mechanism such as a hydraulic brake. Themanipulator arm 110 includes various joints and links that providecontrol or motion in various degrees of freedom. The joints may beprismatic, revolute, or a combination thereof. The tool 113 may be anydevice to contact or perform work on the patient's anatomy including forexample a burr, a saw, an end-mill, a cutter, a laser ablation device,forceps, an endoscope, electrocautery device, a drill, a pin driver, areamer, an ultrasonic horn, a catheter guide, or a probe. The tool 113and manipulator arm 110 are controlled by commands from the computingsystem 104.

The computing system 104 generally includes a planning computer 114having a processor; a device computer 116 having a processor; a trackingcomputer 136 having a processor; and peripheral devices. The planningcomputer 114, device computer 116, and tracking computer 136, may beseparate entities, single units, or combinations thereof depending onthe surgical system. The peripheral devices allow a user to interfacewith the surgical system components and may include: one or moreuser-interfaces, such as a display or monitor 118; and user-inputmechanisms, such as a keyboard 120, mouse 122, pendent 124, joystick126, foot pedal 128, or the monitor 118 may have touchscreencapabilities.

The planning computer 114 contains hardware (e.g., processors,controllers, and memory), software, data and utilities that arepreferably dedicated to the planning of a surgical procedure, eitherpre-operatively or intra-operatively. This may include reading medicalimaging data, segmenting imaging data, constructing three-dimensional(3D) virtual models, storing computer-aided design (CAD) files,providing various functions or widgets to aid a user in planning thesurgical procedure, and generating surgical plan data. The finalsurgical plan may include the three-dimensional bone models havingpoints to facilitate registration, patient identification information,workflow instructions, and operational data for modifying a volume oftissue that is defined relative to the anatomy, such as a set of pointsin a cut-file to autonomously modify the volume of bone, a set ofvirtual boundaries defined to haptically constrain a tool within thedefined boundaries to modify the bone, a set of planes or drill holes todrill pins in the bone, or a graphically navigated set of instructionsfor modifying the tissue. The data generated from the planning computer114 may be transferred to the device computer 116 and/or trackingcomputer 136 through a wired or wirelessly connection in the operatingroom (OR); or transferred via a non-transient data storage medium (e.g.,a compact disc (CD), a portable universal serial bus (USB) drive) if theplanning computer 114 is located outside the OR.

The device computer 116 may be housed in the moveable base 108 andcontain hardware, software, data and utilities that are preferablydedicated to the operation of the surgical device 102. This may includesurgical device control, robotic manipulator control, the processing ofkinematic and inverse kinematic data, the execution of registrationalgorithms, the execution of calibration routines, the execution ofsurgical plan data, coordinate transformation processing, providingworkflow instructions to a user, and utilizing position and orientation(POSE) data from the tracking system 106.

The tracking system 106 of the surgical system 100 includes two or moreoptical receivers 130 to detect the position of fiducial markers (e.g.,retroreflective spheres, active light emitting diodes (LEDs)) uniquelyarranged on rigid bodies. The fiducial markers arranged on a rigid bodyare collectively referred to as a fiducial marker array 132, where eachfiducial marker array 132 has a unique arrangement of fiducial markers,or a unique transmitting wavelength/frequency if the markers are activeLEDs. An example of an optical tracking system is described in U.S. Pat.No. 6,061,644. The tracking system 106 may be built into a surgicallight 134, located on a boom, a stand 142 (as shown in FIG. 2), or builtinto the walls or ceilings of the OR. The tracking system 106 mayinclude tracking hardware 136, software, data and utilities to determinethe POSE of objects (e.g., femur F, tibia T, surgical device 102) in alocal or global coordinate frame. The POSE of the objects iscollectively referred to herein as POSE data, where this POSE data maybe communicated to the device computer 116 through a wired or wirelessconnection. Alternatively, the device computer 116 may determine thePOSE data using the position of the fiducial markers detected from theoptical receivers 130 directly.

The POSE data is determined using the position data detected from theoptical receivers 130 and operations/processes such as image processing,image filtering, triangulation algorithms, geometric relationshipprocessing, registration algorithms, calibration algorithms, andcoordinate transformation processing. For example, the POSE of adigitizer probe 138 with an attached probe fiducial marker array 132 dmay be calibrated such that the probe tip is continuously known asdescribed in U.S. Pat. No. 7,043,961. The POSE of the tip 115 or toolaxis of the end effector tool 113 may be known with respect to a devicefiducial marker array 132 c using a calibration method as described inU.S. Prov. Pat. App. 62/128,857. The device fiducial marker 132 c isdepicted on the manipulator arm 110 but may also be positioned on thebase 108 or the tool 114. Registration algorithms may be executed todetermine the POSE and/or coordinate transforms between a bone (e.g.,femur F, tibia T), a bone fiducial marker array (132 a, 132 b), asurgical plan, and any combination thereof using registration methodsknown in the art such as those described in U.S. Pat. Nos. 6,033,415,and 8,287,522.

Upon assembly of the device tracking array 132 c to the surgical robot102 prior to surgery, the POSE's of the coordinate systems, 132 c and113, are fixed relative to each other and stored in memory to accuratelytrack the end effector tool 113 during the surgery (see for example U.S.Patent Publication 20140039517 A1) relative to the bone anatomy (e.g.,femur F, and tibia T). The POSE data may be used by the computing system104 during the procedure to update the robot and surgical plancoordinate transforms so the surgical robot 102 can accurately executethe surgical plan in the event any bone motion occurs. It should beappreciated that in certain embodiments, other tracking systems may beincorporated with the surgical system 100 such as an electromagneticfield tracking system or a mechanical tracking system. An example of amechanical tracking system is described in U.S. Pat. No. 6,322,567.

Due to the criticality of positioning the base 108 with respect to theanatomy as described above, the optimal position for the robot may bedetermined using several algorithms which heavily rely on global andlocal optimization algorithms. The optimization algorithms may use akinematic model of the robotic system, and a known POSE of the patient'sanatomy (as determined by registering the surgical plan to the boneprior to approaching the patient with the robot) to determine an optimalposition for the base to achieve the desired reachability within theoperative volume such as the points in the cut file, a set ofboundaries, or a set of drill holes or planar cuts, defined in thesurgical plan. The optimization algorithms may also include additionalconstraints for determining the optimal position. The constraints mayinclude manipulator requirements such as the avoidance of a singularity,a joint limit, or a collision of the manipulator arm while executing thesurgical plan. The constraints may include line-of-sight considerationswhere the location of a fiducial marker array relative to the trackingsystem may be optimized for a particular base position or manipulatorarm configuration. The constraints may further include user'spreferences for the position of the base, to provide the user withparticular access points or corridors to the operational site, where therobot is still capable of executing the surgical plan. The preferencesmay also include how the base should be oriented to easily grasp andwield the manipulator arm or end-effector tool if a passive or hapticsurgical robot is used. The algorithm constraints may also includepatient factors such as the patient's body mass index (BMI), theoperating side (e.g., left or right femur), or amount of exposure of thetargeted anatomy. The user's preferences and patient factor constraintsmay be defined in the operating room or in the surgical plan and loadedinto the tracking system 106 or computing system 104 prior to runningthe optimization algorithm. Simulations of the manipulator joints andlinks may also be performed in conjunction with or in lieu of theconstrained optimization algorithms by using the kinematic model atvarious potential base positions relative to the anatomy/plan, until anoptimal position for the base is found to accommodate these manipulatorrequirements. Ultimately, the output of the optimization algorithmsand/or simulations, that is the optimal position of the base, may thenbe used by the operating room (OR) staff to position or re-position therobot with respect to the anatomy.

It should be noted that in certain embodiments, the position andorientation of a targeted bone with respect to a certain worldcoordinate frame is required prior to positioning the robotic system.For example, if a tracking system is present, the current position ofthe bone to the tracking system may be determined using a partial orfull registration process with the digitizer probe 138, where thesurgical plan data may be uploaded to the tracking system 106 prior tothe registration. In a particular embodiment, a user may plan theprocedure intra-operatively and use bone-morphing registrationtechniques (commonly used in imageless computer-aided procedures) todetermine the POSE of the bone with respect to a world coordinate frame.With the bone known in a world coordinate frame, the optimal positionand orientation for the base of the robot with respect to the bone isdetermined using one of the optimization algorithms and methodsdescribed above. Once the optimal position has been determined, theposition needs to be conveyed to the OR staff in an intuitive andaccurate manner.

In an inventive embodiment shown in FIG. 2, a laser, a 2-D image, orholographic image 144 may be used to display the optimal position forthe base 108 of the robot 102 on the floor 146. The indicator mayindicate the position in either absolute coordinate space or relative tothe current position of the robot 102. The absolute indicator shows theoptimal position of the robot in the OR by projecting the footprint 144of the robot base 108 on the floor 146. As the robot moves toward thelocation of the optimal position, the projected image 144 may update sothe footprint 144 remains at the optimal position in absolute coordinatespace. The relative indicator shows the direction that the base 108should be moved or rotated towards, to reach the optimal position, suchas the indicating arrow 150. The projectors 140, such as picoprojectors, are mounted, for example, on the base 108 of the robot 102or on the manipulator arm 110. The projector 140 may also be mountedunderneath the base 108 so the image 144 can be continually updated asthe base 108 moves on top of the image 144 (e.g., projection emanatingfrom the bottom of the base at 145). For this embodiment, in addition tothe position of the bone (e.g., femur F, or tibia T), the position ofthe base 108 of the robot 102 is also needed. This position of the base108 of the robot 102 can be determined by exposing the device fiducialmarker array 132 c attached to the arm of the robot to the trackingsystem 106.

In an inventive embodiment, the robot base 108 may be equipped withlaser distance measurement sensors (LIDARS) 148 and/or cameras toutilize machine vision to position the robot 102. The base 108 usesautonomous robot algorithms to safely navigate itself to the optimalposition while avoiding collisions with the staff and objects in the OR.The position of the base 108 of the robot 102 is needed for thisembodiment, which may be determined with a tracking system 106, or maybe determined with the on-board equipment (e.g., measurement sensors,cameras) and mapping software loaded on the device computer 116. It isappreciated that compared to a robot moving in a dynamic environment,the OR is a comparatively controlled environment and readily mapped. Anautonomous robotic base 108 can move automatically with resort to apowered drive wheel system that includes navigation modules performedfunctions of mapping, localization, collision avoidance, and pathplanning. Variations in patient size and potential interference withanesthesia that might lead to a serious collision or interference withthe procedure are simultaneously avoided by creating an exclusion zonearound the head portion of the OR table 135 that is depicted as the twosmall sections of the table 135 in FIGS. 1 and 2.

In certain inventive embodiments, an occupancy map is learned to combinethe concurrent mapping and localization problem as a maximum likelihoodestimation problem, in which one seeks to determine a most likely mapgiven the data. Likelihood maximization takes into account theconsistency of the odometry as small errors are more likely than largeones, and discounts perceptual consistency, as detailed in S. Thrun, D.Fox, and W. Burgard. A probabilistic approach to concurrent mapping andlocalization for mobile robots. Machine Learning, 31, 1998. In contrastto robots operating in an open space, the surgical robot base 108functions in a controlled and predictable environment of an OR. Acontrolled environment allows an inventive robot to operate within theassumption of Markov localization D. Fox, W. Burgard, and S. Thrun,Markov Localization for Mobile Robots in Dynamic Environments, Journalof Artificial Intelligence Research 11 (1999) 391-427. It uses Bayesrule to incorporate sensor readings and it uses convolution toincorporate robot motion. Initially, the robot does now know its pose;thus, P r(ξ(0)) is distributed uniformly. After incorporating one sensorreading (e.g., RFID, laser or camera) according to the update rule (1),P r(ξ(1)) is distributed. After moving forward, and after incorporatinganother sensor reading, the final distribution P r(ξ(2)) is centeredaround the correct pose raw proximity sensor readings along with adesired robot final location, the path and velocity of the robot arecalculated based on preselected constraints that include the robot mustalways be able to come to a full stop before impact while contendingwith dynamic constrains (e.g., torque limits). Soft constraints are usedto balance the program desire to move directly towards the finallocation by the fastest and shortest route. In combination, theseconstraints ensure safe and smooth local navigation.

The path planner computes paths from one position of surgical action toanother. The collision avoidance mobility software allows the robot base108 to maneuver in the OR. In some inventive embodiments, beyondautomatic braking capabilities to avoid collision, an alarm is providedin the event that a transit trajectory is in process that can lead to acollision, whether under autonomous or manual control.

In a specific inventive embodiment, with reference to FIG. 3, anaugmented reality device 154 illustratively including, but not limitedto Google glass, Microsoft's holo lens, or ODG's glasses is used todisplay the optimal position of the robot 102 within the OR. Asilhouette of the robot base 144 at the optimal position may be shown inthe field of view 156 of the augmented reality device 154. A relativearrow indicator 150 may also be shown in the field of view 156. The POSEof the augmented reality device 154 may be collected either from theinternal sensors (inertial measurement unit (IMU), compass, etc.) of theaugmented reality device 158 or from a augment device fiducial markerarray 132 d mounted on the reality device 154 that can be seen by thetracking system 106.

In a specific inventive embodiment, with reference to FIG. 4, themanipulator arm 110 may assume a certain POSE which represents thedesired position of the bone axis with respect to the axis of the tool113. The user may then move the base 108 of the robot 102 such that thebone (e.g., femur F, or tibia T) is roughly aligned with the axis of thetool 113 by either positioning the base 108 of the robot 102 or thepatient anatomy (i.e. aligning the tool axis and bone axis shown alongaxis 152). This method does not require a tracking system 106 or theregistration information and only depends on the analyses performed onthe surgical plan to assume the certain POSE. In other words, the robot102 assumes a POSE that is desired regardless of the current position ofthe patient. In this embodiment, the initial POSE of the manipulator arm110 may take into account the manipulator requirements, surgeonpreferences, and patient factors. If the manipulator arm 110 has greaterthan 6 degrees of freedom (DOF), the redundant degrees of freedomprovides greater flexibility to achieve the manipulator requirements,surgeon preferences, and patient factors.

In an inventive embodiment the registration algorithm may be used todetermine a suitable position for the robot 102, and then the robot 102assumes a pose which includes the correct base height. The input to thismethod could be the full registration information including the positionand orientation of the patient or at a minimum could be landmarks of theanatomy such as the top of the knee in case of a knee procedure.

A graphical user interface (GUI) method is also provided in which adisplay on monitor 118 is used to provide the user with positioninginformation. For example, if the position and orientation of the robot102 with respect to the bone/patient is known, both the current andoptimal position of the robot base 108 with respect to the patient isdisplayed on a screen. When the base 108 of the robot 102 is moved thescreen is updated to provide a visual assist in moving the robot 102 toan optimal position. In an additional embodiment, a side and top view ofthe bone and the footprint of the base 108 of the robot are displayed,where the color of the bone changes to indicate if the bone is within areachable part of the workspace, and to show a direction of the movementof the base 108 that would lead to a reachable point in the work space.In a specific embodiment, a target symbol (e.g., crosshairs) isdisplayed on the GUI. The target symbol may first appear enlarged on thescreen and then focuses in to the optimal position for the base as thebase is moved to the optimal position.

For fine motions of the robot during the positioning, in an inventiveembodiment an elephant trunk method may be used. In the elephant trunkmethod, a surgeon uses the tool assembly 113 or manipulator arm 110 ofthe robot 102 as a joystick to move the robot 102. This requires apowered robot base 108 that may be moved by electrical steering. Adescription of the elephant trunk method is further described in U.S.Prov. Pat. App. No. 62/142,624, which is hereby incorporated byreference.

It should be appreciated that the methods described above may beextended to the reach of a passive digitizer arm attached to a roboticsystem as described in U.S. Pat. No. 6,033,415 and incorporated hereinin its entirety. The optimization algorithms may further determine anoptimal position for the digitizer or robotic base 108 such that thedigitizer arm complies with any workspace, task, user, or patientrequirements.

After the base 108 has been positioned, the tracking system 106 mayverify that the base 108 is at an optimal position, or at the very leastverify that the the workspace and task requirements are satisfied. Themonitor 118 may display a prompt for the user to acknowledge theposition of the base 108. In a particular embodiment, the user may wantto reposition the base 108 to gain access to particular locations in oraround the operating site, or to have a better grip to wield a passiveor haptic manipulator arm. The monitor 118 may display the currentposition of the base 108 with respect to the anatomy. A triad orrotation cursor may be displayed that allows the user to virtuallyadjust the position of the base on the monitor 118. The tracking system106 or computing system 104 may provide feedback indicating whether thevirtually adjusted position will still accommodate the workspace or taskrequirements. Therefore, the user has an idea of where the base may bere-positioned before actually moving the base 108. Once a new positionhas been determined, any of the methods described above may be used toreposition the base 108 of the robot 102.

Other Embodiments

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or exemplary embodiments are only examples, and arenot intended to limit the scope, applicability, or configuration of thedescribed embodiments in any way. Rather, the foregoing detaileddescription will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiment or exemplary embodiments.It should be understood that various changes can be made in the functionand arrangement of elements without departing from the scope as setforth in the appended claims and the legal equivalents thereof.

The foregoing description is illustrative of particular embodiments ofthe invention, but is not meant to be a limitation upon the practicethereof. The following claims, including all equivalents thereof, areintended to define the scope of the invention.

1. A process for positioning a robot in an operating room containing asurgical table with a bone thereon, the robot having a moveable base, amanipulator arm, an end effector tool attached to the manipulator arm,and a computer containing a surgical plan and hardware to communicatethe plan to the manipulator arm, said process comprising: assuming acertain position and orientation (POSE) with the manipulator arm to forman axis of the end effector tool that represents a desired position ofan axis of the bone; and moving the moveable base or the bone toapproximately align the axis of the bone and the axis of the endeffector tool.
 2. The process of claim 1 wherein the robot assumes acertain POSE based solely on analyses performed on the surgical plan. 3.The process of claim 1 wherein the POSE is based on at least one of:requirements of the manipulator arm to execute a cut-file, surgeonpreferences, and patient factors.
 4. The process of claim 1 furthercomprising registering the bone prior to assuming a POSE with themanipulator arm, where the manipulator arm then assumes a POSE furtherhaving a correct height for the manipulator arm.
 5. (canceled)
 6. Theprocess of claim 1 further comprising a graphical user interface (GUI)to display dynamic positioning information for the robot.
 7. The processof claim 6 wherein the GUI displays a view of the bone and a footprintof the moveable base.
 8. The process of claim 7 further comprisingchanging a color of representation of the bone to indicate if the boneis reachable by the end effector.
 9. The process of claim 6 wherein theGUI prompts a user to acknowledge the POSE.
 10. (canceled)
 11. A processfor positioning a robot in an operating room containing a surgicaltable, the robot having a moveable base, a manipulator arm, and an endeffector tool, said process comprising: determining a first position ofthe moveable base in the operating room, the robot having a programmedsurgical plan; moving the moveable base from an initial position towardsthe surgical table to the determined first position; stopping themoveable base; and engaging the manipulator arm and the end effectortool.
 12. The process of claim 11 wherein the first position is withrespect to anatomy of a patient on the surgical table, where the firstposition is determined based on at least one of: the reach of the endeffector tool and a volume of the anatomy to be modified; the avoidanceof at least one of a singularity, a joint limit, or a collision of themanipulator arm while the end effector tool modifies a volume of theanatomy; a position and orientation (POSE) of a fiducial marker arraymounted on the robot with respect to a POSE of a tracking systemdetector, or a position defined in a surgical plan corresponding to aprocedure type or an operating side of the patient.
 13. The process ofclaim 11 further comprising registering the anatomy of the patient to atracking system prior to determining the first position, wherein thefirst position of the robot is determined using optimization algorithmson the tracking system.
 14. (canceled)
 15. (canceled)
 16. (canceled) 17.(canceled)
 18. (canceled)
 19. (canceled)
 20. The process of claim 11wherein the first determined position is with respect to fixed featuresmapped in the operating room.
 21. The process of claim 11 wherein therobot comprises at least one sensor providing input to the collisionavoidance mobility software as to a dynamic position of the robot baserelative to at least one of the initial position or the first determinedposition.
 22. (canceled)
 23. A robotic surgical system operating on afloor comprising: a computer assisted surgical robot having a base; anend effector tool projecting from said robot; fiducial marker arrays andan optical tracking system for tracking or navigating said end effectorrelative to a subject bone; a surgical plan of operations to beperformed on the subject bone; and a laser, a 2-D image, or imageprojector to project an image of a desired position for the base of saidrobot on the floor to comply with at least one operation of saidsurgical plan of operations.
 24. The system of claim 23 furthercomprising a software module for executing an optimization algorithm todetermine the desired position using two or more inputs, wherein theinputs are selected from the group consisting of: a position of thesubject bone; a position of the at least one operation to be performedon the subject bone; a robot kinematic model; a position of the robot;or a position defined by a user relative to the subject bone.
 25. Thesystem of claim 23 wherein the surgical plan of operations includes acut-file of operations, a virtual boundary constraint of operations, ora graphically navigated set of operations.
 26. The system of claim 23wherein all physical points dictated in said surgical plan of operationsare reachable by said end effector tool when the moveable base ispositioned at the desired position.
 27. (canceled)
 28. The system ofclaim 23 further comprising a laser distance measurement sensors(LIDARS) and machine vision.
 29. The system of claim 23 furthercomprising autonomous robot algorithms to navigate the base to thedesired position.
 30. The system of claim 23 further comprising anaugmented reality device to display the desired position.